#!/usr/bin/env python
#
# Copyright (C) 2020 GNS3 Technologies Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import asyncio
import pytest
import pytest_asyncio
from unittest.mock import MagicMock, patch

from tests.utils import asyncio_patch, AsyncioMagicMock
from gns3server.compute.docker import Docker, DOCKER_PREFERRED_API_VERSION, DOCKER_MINIMUM_API_VERSION
from gns3server.compute.docker.docker_error import DockerError, DockerHttp404Error


@pytest_asyncio.fixture
async def vm():

    vm = Docker()
    vm._connected = True
    vm._session = MagicMock()
    vm._session.closed = False
    return vm


@pytest.mark.asyncio
async def test_query_success(vm):

    response = MagicMock()
    response.status = 200
    response.headers = {'CONTENT-TYPE': 'application/json'}

    async def read():
        return b'{"c": false}'

    response.read.side_effect = read
    vm._session.request = AsyncioMagicMock(return_value=response)
    data = await vm.query("POST", "test", data={"a": True}, params={"b": 1})
    vm._session.request.assert_called_with('POST',
                                           'http://docker/v{}/test'.format(DOCKER_MINIMUM_API_VERSION),
                                           data='{"a": true}',
                                           headers={'content-type': 'application/json'},
                                           params={'b': 1},
                                           timeout=300)

    assert data == {"c": False}


@pytest.mark.asyncio
async def test_query_error(vm):

    response = MagicMock()
    response.status = 404

    async def read():
        return b"NOT FOUND"

    response.read.side_effect = read
    vm._session.request = AsyncioMagicMock(return_value=response)
    with pytest.raises(DockerError):
        await vm.query("POST", "test", data={"a": True}, params={"b": 1})
    vm._session.request.assert_called_with('POST',
                                           'http://docker/v{}/test'.format(DOCKER_MINIMUM_API_VERSION),
                                           data='{"a": true}',
                                           headers={'content-type': 'application/json'},
                                           params={'b': 1},
                                           timeout=300)


@pytest.mark.asyncio
async def test_query_error_json(vm):

    response = MagicMock()
    response.status = 404

    async def read():
        return b'{"message": "Error"}'

    response.read.side_effect = read
    vm._session.request = AsyncioMagicMock(return_value=response)
    with pytest.raises(DockerError):
        await vm.query("POST", "test", data={"a": True}, params={"b": 1})
    vm._session.request.assert_called_with('POST',
                                           'http://docker/v{}/test'.format(DOCKER_MINIMUM_API_VERSION),
                                           data='{"a": true}',
                                           headers={'content-type': 'application/json'},
                                           params={'b': 1},
                                           timeout=300)


@pytest.mark.asyncio
async def test_list_images():

    response = [
        {
            "RepoTags": [
                "ubuntu:12.04",
                "ubuntu:precise",
                "ubuntu:latest"
            ],
            "Id": "8dbd9e392a964056420e5d58ca5cc376ef18e2de93b5cc90e868a1bbc8318c1c",
            "Created": 1365714795,
            "Size": 131506275,
            "VirtualSize": 131506275
        },
        {
            "RepoTags": [
                "ubuntu:12.10",
                "ubuntu:quantal",
                "<none>:<none>"
            ],
            "ParentId": "27cf784147099545",
            "Id": "b750fe79269d2ec9a3c593ef05b4332b1d1a02a62b4accb2c21d589ff2f5f2dc",
            "Created": 1364102658,
            "Size": 24653,
            "VirtualSize": 180116135
        }
    ]

    with asyncio_patch("gns3server.compute.docker.Docker.query", return_value=response) as mock:
        images = await Docker.instance().list_images()
        mock.assert_called_with("GET", "images/json", params={"all": 0})
    assert len(images) == 5
    assert {"image": "ubuntu:12.04"} in images
    assert {"image": "ubuntu:precise"} in images
    assert {"image": "ubuntu:latest"} in images
    assert {"image": "ubuntu:12.10"} in images
    assert {"image": "ubuntu:quantal"} in images


@pytest.mark.asyncio
async def test_pull_image():

    class Response:
        """
        Simulate a response split in multiple packets
        """

        def __init__(self):
            self._read = -1

        async def read(self, size):
            self._read += 1
            if self._read == 0:
                return b'{"progress": "0/100",'
            elif self._read == 1:
                return '"id": 42}'
            else:
                None

    mock_query = MagicMock()
    mock_query.content.return_value = Response()

    with asyncio_patch("gns3server.compute.docker.Docker.query", side_effect=DockerHttp404Error("404")):
        with asyncio_patch("gns3server.compute.docker.Docker.http_query", return_value=mock_query) as mock:
            await Docker.instance().pull_image("ubuntu")
            mock.assert_called_with("POST", "images/create", params={"fromImage": "ubuntu"}, timeout=None)


@pytest.mark.asyncio
async def test_pull_image_skips_image_available_locally():

    with asyncio_patch("gns3server.compute.docker.Docker.query", return_value={"Id": "existing"}) as query_mock:
        with asyncio_patch("gns3server.compute.docker.Docker.http_query") as pull_mock:
            await Docker.instance().pull_image("ubuntu")
            query_mock.assert_called_once_with("GET", "images/ubuntu/json")
            pull_mock.assert_not_called()


@pytest.mark.asyncio
async def test_force_pull_image():

    response = MagicMock()
    response.content.read = AsyncioMagicMock(return_value=b"")

    with asyncio_patch("gns3server.compute.docker.Docker.query") as query_mock:
        with asyncio_patch("gns3server.compute.docker.Docker.http_query", return_value=response) as pull_mock:
            await Docker.instance().pull_image("ubuntu", force=True)
            query_mock.assert_not_called()
            pull_mock.assert_called_with("POST", "images/create", params={"fromImage": "ubuntu"}, timeout=None)


@pytest.mark.asyncio
async def test_pull_image_error():

    class Content:

        def __init__(self):
            self._chunks = [b'{"error": "image not found"}', b""]

        async def read(self, size):
            return self._chunks.pop(0)

    response = MagicMock()
    response.content = Content()

    with asyncio_patch("gns3server.compute.docker.Docker.query", side_effect=DockerHttp404Error("404")):
        with asyncio_patch("gns3server.compute.docker.Docker.http_query", return_value=response):
            with pytest.raises(DockerError, match="image not found"):
                await Docker.instance().pull_image("missing")
            response.close.assert_called_once()


@pytest.mark.asyncio
async def test_pull_image_rejects_incomplete_response():

    class Content:

        def __init__(self):
            self._read = False

        async def read(self, size):
            if self._read:
                return b""
            self._read = True
            return b'{"status": "Pulling"'

    response = MagicMock()
    response.content = Content()

    with asyncio_patch("gns3server.compute.docker.Docker.query", side_effect=DockerHttp404Error("404")):
        with asyncio_patch("gns3server.compute.docker.Docker.http_query", return_value=response):
            with pytest.raises(DockerError, match="Invalid response"):
                await Docker.instance().pull_image("ubuntu")
            response.close.assert_called_once()


@pytest.mark.asyncio
async def test_pull_image_propagates_timeout():

    class Content:

        async def read(self, size):
            raise asyncio.TimeoutError

    response = MagicMock()
    response.content = Content()

    with asyncio_patch("gns3server.compute.docker.Docker.query", side_effect=DockerHttp404Error("404")):
        with asyncio_patch("gns3server.compute.docker.Docker.http_query", return_value=response):
            with pytest.raises(DockerError, match="Timeout while pulling"):
                await Docker.instance().pull_image("ubuntu")
            response.close.assert_called_once()


@pytest.mark.asyncio
async def test_docker_check_connection_docker_minimum_version(vm):

    response = {
        'ApiVersion': '1.01',
        'Version': '1.12'
    }

    with patch("gns3server.compute.docker.Docker.connector"), \
        asyncio_patch("gns3server.compute.docker.Docker.query", return_value=response):
        vm._connected = False
        with pytest.raises(DockerError):
            await vm._check_connection()


@pytest.mark.asyncio
async def test_docker_check_connection_docker_preferred_version_against_newer(vm):

    response = {
        'ApiVersion': '1.52',
        'Version': '29.0.1',

    }

    with patch("gns3server.compute.docker.Docker.connector"), \
        asyncio_patch("gns3server.compute.docker.Docker.query", return_value=response):
        vm._connected = False
        await vm._check_connection()
        assert vm._api_version == DOCKER_PREFERRED_API_VERSION


@pytest.mark.asyncio
async def test_docker_check_connection_docker_preferred_version_against_older(vm):

    response = {
        'ApiVersion': '1.43',
        'Version': '24.0.2',
        'MinAPIVersion': '1.40'
    }

    with patch("gns3server.compute.docker.Docker.connector"), \
        asyncio_patch("gns3server.compute.docker.Docker.query", return_value=response):
        vm._connected = False
        await vm._check_connection()
        assert vm._api_version == DOCKER_MINIMUM_API_VERSION


@pytest.mark.asyncio
async def test_docker_check_connection_docker_unsupported_version(vm):

    response = {
        'ApiVersion': '1.25',
        'Version': '1.13.1',
    }

    with patch("gns3server.compute.docker.Docker.connector"), \
        asyncio_patch("gns3server.compute.docker.Docker.query", return_value=response):
        vm._connected = False
        with pytest.raises(DockerError) as e:
            await vm._check_connection()


@pytest.mark.asyncio
async def test_install_busybox():

    mock_process = MagicMock()
    mock_process.returncode = 1 # means that busybox is not dynamically linked
    mock_process.communicate = AsyncioMagicMock(return_value=(b"", b"not a dynamic executable"))

    with patch("gns3server.compute.docker.os.path.isfile", return_value=False):
        with patch("gns3server.compute.docker.shutil.which", return_value="/usr/bin/busybox"):
            with asyncio_patch("gns3server.compute.docker.asyncio.create_subprocess_exec", return_value=mock_process) as create_subprocess_mock:
                with patch("gns3server.compute.docker.shutil.copy2") as copy2_mock:
                    dst_dir = Docker.resources_path()
                    await Docker.install_busybox(dst_dir)
                    create_subprocess_mock.assert_called_with(
                        "ldd",
                        "/usr/bin/busybox",
                        stdout=asyncio.subprocess.PIPE,
                        stderr=asyncio.subprocess.DEVNULL,
                    )
                    assert copy2_mock.called


@pytest.mark.asyncio
async def test_install_busybox_dynamic_linked():

    mock_process = MagicMock()
    mock_process.returncode = 0  # means that busybox is dynamically linked
    mock_process.communicate = AsyncioMagicMock(return_value=(b"Dynamically linked library", b""))

    with patch("os.path.isfile", return_value=False):
        with patch("gns3server.compute.docker.shutil.which", side_effect=lambda name: "/usr/bin/busybox" if name == "busybox" else None):
            with asyncio_patch("gns3server.compute.docker.asyncio.create_subprocess_exec", return_value=mock_process):
                with pytest.raises(DockerError) as e:
                    dst_dir = Docker.resources_path()
                    await Docker.install_busybox(dst_dir)
                assert str(e.value) == "No busybox executable could be found, please install busybox (apt install busybox-static on Debian/Ubuntu) and make sure it is in your PATH"


@pytest.mark.asyncio
async def test_install_busybox_no_executables():

    with patch("gns3server.compute.docker.os.path.isfile", return_value=False):
        with patch("gns3server.compute.docker.shutil.which", return_value=None):
            with pytest.raises(DockerError) as e:
                dst_dir = Docker.resources_path()
                await Docker.install_busybox(dst_dir)
            assert str(e.value) == "No busybox executable could be found, please install busybox (apt install busybox-static on Debian/Ubuntu) and make sure it is in your PATH"


@pytest.mark.asyncio
async def test_check_host_readiness_warns_when_low(caplog):

    import logging
    from io import StringIO

    docker = Docker()
    files = {
        "/proc/sys/fs/inotify/max_user_instances": "128",
        "/proc/sys/fs/inotify/max_user_watches": "8192",
        "/proc/sys/fs/file-max": "100000",
        "/proc/filesystems": "nodev ext4\nnodev tmpfs\n",
    }

    def fake_open(path, *args, **kwargs):
        return StringIO(files[path])

    with patch("builtins.open", side_effect=fake_open):
        with caplog.at_level(logging.WARNING, logger="gns3server.compute.docker"):
            docker._check_host_readiness()

    message = " ".join(r.message for r in caplog.records)
    assert "max_user_instances=128" in message
    assert "sudo sysctl -w" in message
    assert "modprobe fuse" in message  # FUSE missing -> warned


@pytest.mark.asyncio
async def test_check_host_readiness_silent_when_ok(caplog):

    import logging
    from io import StringIO

    docker = Docker()
    files = {
        "/proc/sys/fs/inotify/max_user_instances": "64000",
        "/proc/sys/fs/inotify/max_user_watches": "524288",
        "/proc/sys/fs/file-max": "1000000",
        "/proc/filesystems": "nodev ext4\nnodev fuse\n",
    }

    def fake_open(path, *args, **kwargs):
        return StringIO(files[path])

    with patch("builtins.open", side_effect=fake_open):
        with caplog.at_level(logging.WARNING, logger="gns3server.compute.docker"):
            docker._check_host_readiness()

    assert not [r for r in caplog.records if r.levelno == logging.WARNING]